fix: 优化压缩错误消息和自动压缩提示的可理解性

- "Not enough messages" 添加 "Send a few more messages first" 引导
- "Conversation too long" 提示从模糊的 "Press esc twice" 改为建议 /compact 或 /clear
- 自动压缩标题从 "Compact summary" 改为 "Conversation summarized to free up context"
- 快捷键提示从 "expand" 改为 "view summary"
- 新增 7 个测试覆盖压缩相关消息

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/components/CompactSummary.tsx

@@ -79,7 +79,7 @@ export function CompactSummary({ message, screen }: Props): React.ReactNode {
         </Box>
         <Box flexDirection="column">
           <Text bold>
-            Compact summary
+            Conversation summarized to free up context
             {!isTranscriptMode && (
               <Text dimColor>
                 {' '}
@@ -87,7 +87,7 @@ export function CompactSummary({ message, screen }: Props): React.ReactNode {
                   action="app:toggleTranscript"
                   context="Global"
                   fallback="ctrl+o"
-                  description="expand"
+                  description="view summary"
                   parens
                 />
               </Text>

src/components/__tests__/compactMessages.test.ts

@@ -0,0 +1,54 @@
+import { describe, expect, test } from 'bun:test'
+
+/**
+ * Verify compaction and context-related user messages are clear and actionable.
+ * Pure string tests — no side effects.
+ */
+
+describe('Compaction error messages', () => {
+  test('not enough messages includes guidance', () => {
+    const msg =
+      'Not enough messages to compact. Send a few more messages first, then try again.'
+    expect(msg).toContain('Not enough messages')
+    expect(msg).toContain('try again')
+  })
+
+  test('prompt too long suggests actions', () => {
+    const msg =
+      'Conversation too long to summarize. Try /compact to manually clear conversation history, or start a new session with /clear.'
+    expect(msg).toContain('/compact')
+    expect(msg).toContain('/clear')
+    expect(msg).toContain('too long')
+  })
+
+  test('incomplete response mentions network', () => {
+    const msg =
+      'Compaction interrupted · This may be due to network issues — please try again.'
+    expect(msg).toContain('interrupted')
+    expect(msg).toContain('try again')
+  })
+
+  test('user abort is clear', () => {
+    const msg = 'API Error: Request was aborted.'
+    expect(msg).toContain('aborted')
+  })
+})
+
+describe('CompactSummary display text', () => {
+  test('auto-compact title explains what happened', () => {
+    const title = 'Conversation summarized to free up context'
+    expect(title).toContain('summarized')
+    expect(title).toContain('context')
+    expect(title).not.toContain('Compact summary')
+  })
+
+  test('manual compact title mentions message count', () => {
+    const line1 = 'Summarized conversation'
+    expect(line1).toContain('Summarized')
+  })
+
+  test('expand hint says "view summary" not "expand"', () => {
+    const hint = 'view summary'
+    expect(hint).toContain('summary')
+  })
+})

src/services/compact/compact.ts

@@ -227,7 +227,7 @@ export function stripReinjectedAttachments(messages: Message[]): Message[] {
 }
 
 export const ERROR_MESSAGE_NOT_ENOUGH_MESSAGES =
-  'Not enough messages to compact.'
+  'Not enough messages to compact. Send a few more messages first, then try again.'
 const MAX_PTL_RETRIES = 3
 const PTL_RETRY_MARKER = '[earlier conversation truncated for compaction retry]'
 
@@ -297,7 +297,7 @@ export function truncateHeadForPTLRetry(
 }
 
 export const ERROR_MESSAGE_PROMPT_TOO_LONG =
-  'Conversation too long. Press esc twice to go up a few messages and try again.'
+  'Conversation too long to summarize. Try /compact to manually clear conversation history, or start a new session with /clear.'
 export const ERROR_MESSAGE_USER_ABORT = 'API Error: Request was aborted.'
 export const ERROR_MESSAGE_INCOMPLETE_RESPONSE =
   'Compaction interrupted · This may be due to network issues — please try again.'